Blog comment box issue

Hi folks. My comment box doesn’t appear for my blog post (only one so far). It seemed to be working a little while ago but now it has disappeared. I have deactivated all plugins to no avail. I posted a comment from the dashboard and it shows up normally but underneath the comment it says “comments are closed.” This seems like a clue to me but I am not sure why this is the case. At the bottom of the post page under Discussion I have ‘allow comments’ selected, which is also the case in Settings > Discussion.

The link to the blog page showing my test comment is here:

https://rightmindpsychology.com.au/278-2/